Lunch box



FIG. 1 is a perspective view of the lunch box in accordance with the design.

FIG. 2 is a front view thereof, with the rear view being substantially identical thereto.

FIG. 3 is a right side view thereof, with the left side view being substantially identical thereto.

FIG. 4 is a top view thereof; and,

FIG. 5 is a bottom thereof.

The portions of the drawings shown in broken lines represent environmental structure and form no part of the claimed design. 

The ornamental design for a lunch box, substantially as shown and described. 